Middle cerebral artery occlusion (MCAO)/reperfusion model

The MCAO model was performed as previously described, with slight modification (13). In brief, the rats were anesthetized with 350 mg/kg chloral hydrate. Then, the internal carotid artery (ICA), right common carotid artery, and external carotid artery (ECA) of each rat were carefully dissected. A 4-0 nylon filament with a rounded tip was inserted into the ICA through the ECA stump and pushed gently towards the middle cerebral artery (MCA) to achieve MCAO. After MCAO for 2 h, the filament was gently removed to initiate reperfusion and the skin was sutured. The rats in control group underwent the same surgical procedure except for the occlusion/reperfusion. The rectal temperature of each rat was maintained at 37±0.5 °C with a heating pad from the start of surgery.